Validation Services for Anechoic Chambers

We are offering validation services with partnering third party, independent and accredited calibration laboratories. Get validation services for your existing anechoic chambers, or for the ones that will be built. 

Worldwide onsite validation services

If you have an anechoic chamber, we are able to validate it according to international standards. Tests and measurements are done by third party and independent agencies. We are partnering with independent validation service providers and  ISO/IEC 17025 accredited calibration laboratories which are accredited by UKAS, DakkS, Akkreditierung Austria and some other accreditation agencies. Shielding attenuation/effectiveness, Normalised Site Attenuation (NSA), Field Uniformity (FU), sVSWR, ETSI and other performace measurements are done and certified. Validation or calibration team visits the anechoic chamber and perform on-site measurements to validate your anechoic chamber. Validation report is issued after onsite measurements are completed and this will be the proof that your anechoic chamber fulfils the requirements. Our international network of calibration laboratories allow us to offer these services worldwide.

1) Shielding Effectiveness (SE) Measurements

SE is measured in accordance with EN 50147-1. Typical measurement frequencies are:

A validation according to IEEE Std. 299 is possible and when the test is performed at certain test points the price calculation according to the Table is applicable. Selection of these frequencies is possible, any other frequencies upon request. The exact location of the test points will be defined together with the customer on site as it is necessary to have full access to all test points. A leakage test at 433 MHz will be performed when requested at time of order. Please nominate an assistant to our engineer for setting up the equipment and to handle ladders, tripods and the like. He needs to be familiar with the circumstances on the site, e.g. arranging stable electric power supply or arranging electric light at dark conditions and shall be able to fix any possible leakages by cleaning or adjusting the shielding enclosure. If the SE results do not fulfil the acceptability criteria or customer’s specification, and a modification of the shielding is necessary, and waiting time is charged additionally. 

2) Normalised Site Attenuation Reference Site Method up to 1 GHz

2.1) Validation of Semi Anechoic Chambers and Open Area Test Sites below 30 MHz

The Normalised Site Insertion Loss (NSIL), and Reference Site Method (RSM) respectively is measured according to latest developments in the standardization committees (Draft Document CIS/A/1307A/CC of CISPR 16-1-4). Frequency range from 9 kHz to 30 MHz; Magnetic field antennas (Loop) in all three orthogonal directions at a height of 1.3 m; volumetric test method (please specify test volume diameter); test distance: 3 m, 5 m or 10 m, any other distance upon request.

2.2) Validation of Semi Anechoic Chambers SAC and Open Area Test Sites OATS

Reference Site Method (RSM) and NSA respectively is measured in accordance with CISPR 16-1-4 Ed. 4.1 from 2020-06 (clause 6.6, 6.8) and ANSI C63.4a -2017 (NSA, Annex D) respectively. Frequency range from 30 MHz to 1 GHz; broadband antennas in horizontal polarisation at 1 m and 2 m height and in vertical polarisation at 1 m and 1.5 m height; volumetric test method (please specify test volume diameter); test distance: 3 m, 5 m or 10 m; any other distance or volume height upon request. The height scan of the receive antenna is carried out in the range of 1 to 4 m above ground plane, any other scan range upon request. The automatic antenna mast with GPIB interface must be provided by the customer and the type of the mast shall be specified prior the testing.

2.3) Fully Anechoic Room (FAR) Validation

Fully anechoic rooms (FAR) are validated in accordance with CISPR 16-1-4 Ed. 4.1 from 2020-06 (clause 6.10) – Reference Site Method (RSM): frequency range from 30 MHz to 1 GHz; broadband antennas (biconical and log. per. for 3 m distance or BiLog antenna for 5 m distance) in horizontal and vertical polarisation; volumetric test method (fixed distance, with “tilting”): 5 points in 3 heights each; nominal test distance: 3 m – any other distance upon request; “Site Reference Method” for antenna calibration applied.

3) Site Validation above 1 GHz

3.1) Site VSWR

Site VSWR measurement is done in accordance with CISPR 16-1-4 Ed. 4.1 from 2020-06 (clause 7, 7.6): frequency range from 1 GHz to 18 GHz, 50 MHz steps; broadband omnidirectional antennas in horizontal and vertical polarisation; volumetric test method is applied (please specify test volume: diameter, height and location in the chamber); test distance 3 m, 5m or 10 m – any other distance upon request. The ground plane has to be covered with sufficient absorbing material. For measurement distances of 5 m and 10 m, the floor absorbers needs to be installed by the customer. As the receive antenna type can have a large influence on the test result, the same antenna should be used for validation as the customer will use for emission testing. We recommend that the owner of the chamber provides his antenna (the type of the antenna shall be specified at time of order) for the test in agreement with the chamber manufacturer.

3.2) Transmission Loss (TL) Measurement (not standardized)

TL measurement is done in free space environment in the frequency range from 18 GHz to 40 GHz using horn antennas in horizontal and vertical polarisation at 1 m and 2 m height. The volumetric test method is applied (please specify test volume). At all test points the antennas are mounted at the same height, they face each other and are adjusted to the test distance of 3 m. The ground plane has to be covered with absorbing material.

4) Field Uniformity (FU) Measurements

The purpose of the FU measurement is to characterise the uniform field area (UFA): 16 points in a vertical plane of 1,5 m x 1,5 m, 26 MHz to 40 GHz, 1 % frequency step size, horizontal and vertical polarisation of the transmit antenna. Up to 1 GHz the transmit antenna is fixed at ONE position to test the uniformity of the 16 points. For Windowing the transmit antenna is set up at 9 different points to test the uniformity. This windowing may be used in the frequencies above 1 GHz and it must be used for frequencies higher than 18 GHz.

FU measurements are done to validate the uniformity of the field and not to calibrate the setup for the radiated susceptibility testing according to IEC 61000-4-3 or EN 61000-4-3. For a FU validation above 18 GHz, power amplifiers need to be provided by the customer. The recording of the field strength, 40 cm above the earth reference plane, is only done at additional costs upon request. The transmit antenna and power amplifier may influence the UFA performance. The new draft of the IEC 61000-4-3 Ed. 4 allows a different starting height of the UFA. If the requested height is different to 80 cm, please specify, as we need to check our compatibility.

5) Reverberation Chamber Validation

The Reverberation Chamber validation (mode-tuning method applied) for one tuner is done according to IEC 61000-4-21 and ISO 11452-11. The position, size of the test volume and the applicable acceptability criterion shall be specified prior the validation.
The measurements of the field uniformity (FU) for the empty and loaded chamber are performed. The properties: antenna validation factor (AVF), chamber characterization factor (CCF), antenna characterization factor (ACF), chamber loading (MLF), Quality Factor (Q), Time Constant (Τ) and Insertion Loss (IL) are calculated accordingly.
The FU validation is conducted with a minimum tuner step as possible in order to meet the standard requirements: 12 tuner steps are applied. Increase of steps is done if the acceptability criterion is not met. The absorbing material, required for chamber loading, must be provided by the customer.
The TX antennas need to be installed inside the chamber by the manufacturer or the owner of the chamber.
Please provide a list of equipment (antennas, power amplifiers, signal generator, power meters) which can be provided by the customer for the testing. Typically, we are only providing a traceable calibrated field probe.
Prior the testing, we need to adapt our measurement software for the required measurement instruments and also for the controller of the stirrer.

List of on-site validation services for EMC test sites

All applicable test site validation measurements are listed below, you can ask any of them: